Foveated Rendering

1. A processing system configured to render one or more images of a scene, the processing system comprising: rendering logic configured to process graphics data to generate an initial image comprising pixel values representing an image of the scene; region identification logic configured to identify one or more regions of the initial image; ray tracing logic configured to perform ray tracing to determine ray traced data for the identified one or more regions of the initial image; and update logic configured to update the initial image using the determined ray traced data for the identified one or more regions of the initial image by adding detail to the identified one or more regions of the initial image, to thereby determine an updated image to be outputted for display; wherein the rendering logic and the ray tracing logic are configured to operate asynchronously; and wherein the ray tracing logic, the region identification logic and the update logic are configured to operate at a first frame rate and the rendering logic is configured to operate at a second frame rate, said first frame rate being faster than said second frame rate.

2. The processing system of claim 1 wherein the rendering logic is configured to process the graphics data using a rasterisation technique to generate the initial image.

3. The processing system of claim 1 wherein the rendering logic is configured to process the graphics data using a ray tracing technique to generate the initial image.

4. The processing system of claim 1 wherein the initial image is a lower detail image than the updated image.

5. The processing system of claim 1 further comprising gaze tracking logic configured to determine one or more gaze positions for the initial image, wherein the region identification logic is configured to receive one or more indications of the one or more determined gaze positions, and to identify the one or more regions of the initial image based on the one or more determined gaze positions.

6. The processing system of claim 5 wherein the gaze tracking logic is configured to implement a predictive model to anticipate movements in gaze.

7. The processing system of claim 5 wherein one of the one or more identified regions of the initial image surrounds one of the one or more determined gaze positions, thereby representing a foveal region.

8. The processing system of claim 7 further comprising a camera pipeline which is configured to: receive image data from a camera which is arranged to capture images of a user looking at a display on which a rendered image is to be displayed; and process the received image data to generate a captured image; wherein the gaze tracking logic is configured to analyse the captured image to determine the gaze position for the initial image.

9. The processing system of claim 8 wherein the ray tracing logic and the rasterisation logic are implemented on a graphics processing unit, and wherein the camera pipeline and the graphics processing unit are implemented as part of a system on chip (SOC).

10. The processing system of claim 1 wherein the region identification logic is configured to analyse the initial image to determine one or more regions of high frequency, wherein the one or more determined regions of high frequency are one or more identified regions of the initial image.

11. The processing system of claim 1 further comprising time warping logic configured to apply an image warping process to the updated image before it is sent for display.

12. The processing system of claim 1 further comprising acceleration structure building logic configured to determine an acceleration structure representing the graphics data of geometry in a scene of which an image is to be rendered.

13. The processing system of claim 12 wherein the processing system is configured to render a plurality of images representing a sequence of frames, and wherein the acceleration structure building logic is configured to determine the acceleration structure for a current frame by updating the acceleration structure for the preceding frame.

14. The processing system of claim 1 wherein the processing system is arranged to be included in a virtual reality system or an augmented reality system.

15. A method of rendering one or more images of a scene at a processing system, the method comprising: processing graphics data to generate an initial image comprising pixel values representing an image of the scene; identifying one or more regions of the initial image; performing ray tracing to determine ray traced data for the identified one or more regions of the initial image; and updating the initial image using the determined ray traced data for the identified one or more regions of the initial image by adding detail to the identified one or more regions of the initial image, to thereby determine an updated image to be outputted for display; wherein said performing ray tracing, said identifying one or more regions of the initial image and said updating the initial image are performed at a first frame rate, and wherein said processing graphics data to generate an initial image is performed at a second frame rate, wherein the first frame rate is faster than the second frame rate.

16. The method of claim 15 further comprising displaying an image based on the updated image.

17. The method of claim 15 wherein the processing graphics data to generate an initial image is performed at an asynchronous rate to the performing ray tracing to determine traced data.

18. A non-transitory computer readable storage medium having stored thereon a computer readable dataset description of an integrated circuit that, when processed in an integrated circuit manufacturing system, causes the integrated circuit manufacturing system to manufacture a processing system comprising: rendering logic configured to process graphics data to generate an initial image comprising pixel values representing an image of a scene; region identification logic configured to identify one or more regions of the initial image; ray tracing logic configured to perform ray tracing to determine ray traced data for the identified one or more regions of the initial image; and update logic configured to update the initial image using the determined ray traced data for the identified one or more regions of the initial image by adding detail to the identified one or more regions of the initial image, to thereby determine an updated image to be outputted for display; wherein the rendering logic and the ray tracing logic are configured to operate asynchronously; wherein the ray tracing logic, the region identification logic and the update logic are configured to operate at a first frame rate, and the rendering logic is configured to operate at a second frame rate, the first frame rate being faster than the second frame rate.